Operator&#39;s position circuit



July 15, 19`41.

F. S. IRVINE OPERATORS POSITION CIRCUIT 2 sneetsLshet 1 Filed April 3, 1940 July l5, 1941.

4To Pos @usr on /v/aHr ALARM OPERATORS POSITION CIRCUIT Filed April, 1940 2 Sheets-Sheet 2' /Nl/E/VTOR @y F. s. maf/Ng A 7' TURA/EV Patented July 1.5, 1.941

UNITED STATES l 2,249,32' Y orE-RA'roR-s POSITION GIRfJifJI'I.V

Frank S. Irvine,- Greenlawn, k assigner to. Bell Telephone Laboratoria Incorporated., New York, N. Y., a corpoationofNewXork i 'f ApplicationAprl 3, 1940, SerallNo. 327,563:

e aiclaims. icl; 17a-'2tlg l v 'I-'his invention relates to telephone systems and has-for its-object to increaseftheeiciencyfof such systems.

When'manual-and dial telephone exchanges-are interconnected it is customaryto employ-operators at; the dial exchanges toreceive instructions from the manualexchanges and to control the dial equipment in accordance therewith. In one` such system link circuits interconnect the incoming trunks, the operators positions andthe register senders. The incoming trunks are arranged in twol groups and the linkA circuits and positionsare similarly-grouped. A few operators positions are providedhwhichserve both sets of link circuits. Y Since-the link circuits test the-operatorspositions insuccession, the common positions are tested twice as often as the different group positions andI it hasbeen-found that the operators at the common positions are sometimes excessively busy. Y

In accordance with the present invention, means` is provided for rendering common posi.- tions available at a later-stage in the handling of a` call than that at which the group operators become availablet Meansis-also provided when calls are'waiting torender the common positions availablevat the'- same stage as. the group operators.

'Ilhefeatures of. the invention will become-more apparenti from a considerationv 'of theiollowing descriptionitakenin.connection-with the drawings in-whiehz Fig. 1` shows two groupoperators positionsand two commonbperators positions; and i Eig. 2-shows two links. of eachgroupand tw calls waiting-signal circuits. Y

These drawings are based on the disclosures of Patent` 1,855,616,- grantedto W. E. Stevens, April 26., 1932,- and on Patent 2,060,585, grantedfon No vember `10, 1936to C. G. Miller. Where possible, thesame reference characters will be employed-as are'used'in these patents. Where the same piece ofA equipment appears more than once, suflixes Vsuch as AI, Bl, etc. will be employed. Reference is hereby made to the above-mentioned patents forcomplete descriptions of thev operationsinvolved.

Inthedrawings, group operators positionsAl and A2.cfgroup A are shown at the -leftof Fig. 1 and common .operators positions C' I and C2 :are shown at the right offFig; 1.

In Fig. 2 fourlink circuits, two from each -group are represented by. the brush oi-the position .finder` over` which ,the link; tests for an vidle, position. In f, addition.; one.- sequence switch. cam, namely,

.that over which-the calls waiting signalv circuit is controlled, is-shown for each link.

vReferringtok the rst group position A-I, when an operator occupies the position, the connection of her headset thereto operates relay I405AI. Relay MESA I- connects ybattery throughresistance I'422Al;l over the upper' backv contact of relay MDTAI andJ the normal ontacts-ofjack |408Al to conductor I409AI: which-is multipled toA one contact ofY each off the banks to which brushes E OSAI and 506A!V as well asthe remainingv test brushes ofthe A groupof linkshhave access.A Similarly, when position A2" is occupied: anv idle 'battery willbe connected.l over co-nductor |409A2 to contacts of` the banks to which'v brushes 506m, 506A?, etc. have access. `The test-brushes-YEUIBBIV., 566B2, etc. of link group-B haveaccess in-common y to 1 a B1 group of` operators positions.

The e commonv operators? positions, when occupied' and idle, connectedV batteryl toconductors MOSCI, M0902', etc. and` these conductors-are multipled. to bank terminals: to which thetest brushes of both `groups of. linkshave access. l

described in. thel above-identified'Y Stevens patent,when a linkI is seized? it hunts for an idle operators .position and establishes a..y connection therewith, over.` which the-positionis marked busy and a talkingconnectionfis established: over which the operator receivesthe wanted number. When .the operator starts to v `operate her keyset to record the number, relay MDJAI. operates, opening the connection of batteryf to conductor MBQAI and permitting the link to advance.

In the circuit. disclosed; in the-Stevens patent each operator has akeyrsetiwhichincludes arow of. keysv for. eachv digit .offra telephone designation and the, recorded number is. transmitted: to. the associated sender by. meansof` a series of code pulses. Whena key. has beenloperatedin each row4` ofA the key-set, the lockingv circuit: of relay HolA-l is opened andthatrelay-.releases toirestore the connectionl of batteryv tofconductor I409Al. so that the operator-spositionmay be selected and the operatormay receive another wanted number while the ycode ypulses are being transmitted. When-the-pulsing circuitis ready to send outthelast digit relayM lA'If is operated; T-he functioningof=a common operators posi;- tion, for example, position CI, is-very similar to thatof the groupvroperator. However, each com,- mon `position-.isprovided with two rel-ays200 and 20|, one for each group-ofi links, andiconductor I 40 9C l which is A'marked Abyl-batterywhen .position Cl -is idle, is .connected over the back.` ContactA of relay..i 2011'. to'- bank contacts! tov which brushes 506AI, 596A2, etc. of the group A links have access and over the back-contact of relay 20| to the bank contacts to which brushes 506Bl, 506B2, etc. of the group B links have access. Relays 203 and 204 connect conductor |409C`2 to the links of groups A and B, respectively.

When common position C| is seized and relay |40'ICI operates, the operating ground for relay |401C| is extended over conductor |00, lower back contact of relay 205, to the upper winding of relay 200 and battery and over the lower back contact of relay 206 to the upper winding ofl relay 20| and battery. Relay 200 operates and locks in a circuit from battery through `its lower winding and front contact, outer `'lower back contact of relay 201, to ground.v at 'the back contact of relay 4| ICI. In a similar manner relay 20| operates and locks over the outer lower back contact of relay 208 to ground at the back contact of relay 4||C|. Relays 200 and 20| disconnect conductor |409C| from the bank contacts of the link groups A and B respectively. The release of relay |401C| at the end of the keyingoperation reconnectsbattery to conductor |409C| but with relays 200 and 20| operated, the position is not marked idle to the group switches until relay ll |C| operates, when the number has been transmitted to the'sender. This delay in marking the common position available is elective, when group positions are available, to` equalize the seizure oi the group and common positions.

However, when oneor the other group of positions is vacated,this delay is removed so that the common operators may serve that group. When a position, for example position AI, is occupied operating relay |405AI, ground is connected kto conductor` operating relay 209. As long as yone operators position of the group is occupied, relay 209 will be held operated, but when all of the positions are vacated relay 209 releases, operating relay 201. Relay 20'! in turn operates relay 205 and these relays open the operating and locking circuits of relays ,200 and 203 so that the common positions become available at the same stage as the group positions. However, as regards group B, relays 20| and 204 still function and the'common positionsare held busy to this group until the later time.

The group B positions controlla relay 2 0 which in turn' controls relays 2,08 and 206 to remove the delay at the common positions when all B positions are vacated. s

There may be` times when, although group positions are available, the calling rate is high enough to overload one group or the other For the purposes.- of indicating such` a conditionan arrangement knownas a calls waiting signal circuit has been provided `and this circuit is disclosed in the above-identified Miller patent. Two such circuits have been indicated at the right of Fig. 2. `While each link is hunting for a position, ground is connected over cam |2AI for example, ,through resistance |3A| over conductor 40A through the upper winding of polarized relay IBA to battery through resistance l'lA.v Each oi the group positions closes a circuit which may be traced by way of, example from battery through resistance 5A and inner upper contact of Vrelay |405Al, in parallel with resistance I'IA and battery. As pointed out in the Millerpatent, the resistances are selected to cause Vrelay 6A to operate at a predetermined relative congestion of incoming calls, lat which point relay 2 |A operates, lighting lamp 24A.. 4Voltmeter;relay` 22Av closes its contact at` a voltage which represents' aditferent relative congestion, operating relay 28A and lighting lamp 3|A. Keys 2|| and 2|2 are provided to cancel the delay for the common positions at either desired point of congestion. With key 2|| operated, the operation of relay 2|A operates relay 205 to prevent the operation of relays 200 and 203, while with key 2| 2 operated, relay 205 is operated under the control of relay 28A. It may be noted, that when the delay is removed by the calls waiting signall circuit, the operating circuits of relays 200 and 203 are opened immediately, but the locking circuits remain closed, so that if a call has locked in the delay, it will be completed on that call but not on subsequent calls.

A similar calls waiting signal circuit is provided for the group B links and positions.

What is claimed is:

1. In a telephone system, link circuits divided into groups, operators positions individual to said groups, operators positions common to said groups, means to associate one of said link circuits with one of said positions, means to mark said positions available when occupied and idle, means responsive to the association of said link circuit with an available position to remove said marking, means to restore said marking at a particular stage of the operation of said position equipment, and means individual to said common positions to delay the effect of Asaid restoring means until a later stage ofthe operation of said comman position equipment.

2. In a telephone system, link circuits divided into groups, operators positions individual to said groups, operators positions-common to said groups, means to associate one of said link circuits with one of said positions, means to mark said positions available when occupied and idle, means responsive to the association of said vlink circuit with an available position to remove said marking, means to restore said marking at a particular stage of the operation of said position equipment, means individualI to said common positions to delay the effect of said restoring means until a laterstage of the operation of said common position equipment, and means under the control `of said group positions to cancel said delay.

3. Ina telephone system, link circuits divided into groups, operators positions individual to said groups, operators? posi-tions common to said groups, means to associate one of said link circuits with one of said positions, means to mark said positions available when occupied and idle, means responsive to the association of said link circuit with an available position to remove said marking, means to restore said marking at a particular stage of the operation of said position equipment, means individual to said'common positions to delay the eifect of said restoring means untilalater stage of the operation of said c-ommon position equipment, and, means under the control of one of said groups of positions to cancel said delay with regard to said group.

4..In a telephone system,` link circuits divided into groups, operators positions individual to said groups, operators positions common to said groups, means to associate one cf said link circuits with one of said positions, means to mark said positions available by connecting ai predetermined potential to aconductor to which "said link circuits have access, lmeans in said position toremove .said potentialA from said conductor during the operation of said position-equipment,

means to reconnect said potential to said conductor a-t a particular stage of Ithe operation of said position equipment and means individual to said common positions t-o disconnect said conductor from said link circuits until a later stage in the operation of said position equipment.

5. In a telephone system, link circuits divided into groups, operators positions individual 'to said groups, operators positions common to said groups, means to associate one of said link circuits With one of said positions, means to mark said positions available by connecting a predetermined potential to a conductor to which said link circuits have access, means in said position to remove said potential from said conductor during the operation of said position equipment, means to reconnect said potential to said conduotor at a particular stage of the operation or said position equipment, and means individual to said common positions -to delay the connection of said conductor to said link circuits until a later stage in the operation oi said position equipment, and means under the control of said group positions to cancel said delay. I

6. In a telephone system, link circuits divided into groups, operators positions individual to said groups, operators positions common to said groups, means to associate one of said link circuits with one of said positions, means tomark said positions available by connecting a predetermined poten-tial to a conductor to which said link circuits have access, means in said position to rem-ove said potential from said conductor during the operation of said position equipment, means to reconnect said potential to said conductor at a particul-ar stage of the operation of said position equipment, means at each common position individual to each subgroup of links to disconnect said conductor from said link circuits until a later stage in the operation of said position equipment, and means under the control of one oi said groups of positions Itoprevent the operation of the disconnecting means individual to that group to render said common positions available -at said particular stage.v

'7. In a telephone system, link circuits divided into groups, operators positions individual to said groups, operators positions common to said groups, means to associate one of said link circuits With one of said positions, means to m-ark said positions available by connecting a predetermined potential to a conductor to which said link circuits have access, means in said position to remove said potential from-said conductor during the operation of said position equipment, means to reconnect said potential to said conductor at a particular stage of the operation of the position equipment, means at each common position individual to each group of links to disconnect said conductor from said link circuits until a later stage in the operation of said position equipment, and means under the control of either of said gro-ups of positions to prevent the operation of the disconnecting means individual to that group to render said common positions available at said particular stage.

8. In a telephone system, link circuits divided into groups, operators positions individual to said groups, operators positions common to said groups, means to associate one of said link -circuits Wi-th one of said positions, means to mark said positions available when oc-cupied and idle, means responsive to the association `of said link circuit with an available position to remove said marking, means to restore said marking at a particular stage of the operation of said position equipment, means individual to said common positions to delay the effect of said restoring means until a later stage of the operation of said common position equipment and means effective if all of the positions of one of said groups are vacated to render said c-ommon positions available to said group at said particular stage.

9. In a telephone system, link circuits divided into groups, operators positions individual to said groups, operators positions common to said groups, means to associate one of said link circuits With one of said positions, means to mark said positions available When occupied and idle, means responsive to the -association of said link circuit With an available position to remove said marking, means to res-tore said marking at a particular stage of the operation of said position equipment, means individual to said common positions to delay the effect of said restoring means until a later stage of the operation of said common position equipment and means effective if a particular relative busy condition exists in one of said gro-ups of positions to render said common positio-ns available to said group at said particular stage.

FRANK S. IRVINE.V 

